The Regiment was formed as 5th Regiment Royal Horse Artillery in 1939 and consisted of K Battery and G Battery (Mercers Troop) RHA. K Battery was the current Riding Troop at St Johns Wood. In 1940 the Regiment formed part of the British Expeditionary Force to France and after Dunkirk moved to North Africa, where it joined 7th Armoured Division.

Along with 7th Armoured Division the Regiment fought throughout the Western Desert and for a limited period took part in the Italian Campaign. On return to the UK in early 1944 it then took part in the Normandy landings and fought in Northwest Europe to VE Day. In 1946, CC Battery became C Battery.

Because of the reorganisation of the Royal Horse Artillery in 1958, the Regiment became 5th Field Regiment RA. On the 1st February 1958, C Battery moved to 3rd RHA and G Battery (Mercer's Troop) moved to 4th RHA. P Battery (The Dragon Troop) left 4th RHA and Q (Sanna's Post) Battery moved from 10th Field Regiment on the 5th February 1958 to join K Battery and form the Regiment. After a short period near Crickhowell, the Regiment left there in September 1958 for a 3-year tour of Hong Kong. After an enjoyable tour equipped with 25lb guns the Regiment returned to Salisbury Plain in Southern England in October 1961 as 5 Light Regiment RA.

During its stay at Perham Down, the Regiment had many equipment changes. In 1961 K Battery had 5.5" guns while P and Q Batteries were equipped with 25 pdrs; then in 1962 all the Batteries were allotted 4.2" Mortars as well as other guns.

In 1963 the Regiment converted to 105mm Pack Howitzers and took part in exercises in Libya, Canada and Norway with this versatile new gun. In August/September of 1964 the Regiment moved to the British Army of the Rhine (BAOR) in Germany and reverted to its title of 5th Field Regiment RA and was stationed in Gutersloh as a Close Support Regiment. Once again K Battery had 5.5" guns and P and Q Batteries 25 pounders, but these later gave way to the Abbot Self Propelled (SP) gun in 1966.

Sports wise Skiing and Hockey feature as the major successful sports before the regiment returned to Southern England in 1969 this time to Bulford. The Regiment now formed part of 3rd Division and the Strategic Reserve. The next three years were dominated by four emergency tours of Northern Ireland (NI) before the move to Hildesheim, Germany in 1972 and re-equipping with 175mm Guns (M107 SP), the Regiment again changed its name to 5th Heavy Regiment RA.

18 Battery joined the Regiment in February 1977 on the disbandment of 42 Regiment RA. After 12 years at Tofrek Barracks in Hildesheim, the Regiment moved to West Riding Barracks in Dortmund in 1984. 18 (Quebec 1759) Battery and Q (Sanna's Post) Battery (which was renamed as 74 Battery (the Battle-Axe Company)) left the Regiment to join 32 Heavy Regiment RA. 73 (Sphinx) Locating Battery moved from 94 Locating Regiment to 5th Regiment in January 1985 and was renamed Q (Sanna's Post) Battery.During this period, the Gun Batteries both carried out operational tours of Northern Ireland.

On the 2nd November 1990, 73 (Sphinx) Battery was formed as 73 (Sphinx) Observation Battery, from the OP Troops of 5 and 32 Regiments. In 1991, many of the soldiers were attached to 32 Regiment RA for Operation Granby, the Gulf War. K (Hondeghem) Battery were attached to 18 (Quebec 1759) Battery and P Battery (The Dragon Troop) were attached to 74 Battery (The Battle-Axe Company). In addition, several soldiers went with 40 Regiment RA earlier in the operation. 73 (Sphinx) OP Battery joined the 16/5th Lancers and was organised into two Forward Air Control parties, one Tactical Air Command Post and five Armoured Mobile OPs.

After Operation Granby, the Regiment converted from the M107 SP Gun to the Multiple Launch Rocket System (MLRS). The Regiment carried out several dry and live firing exercised on Hohne Ranges. On 1st April 1993, 73 (Sphinx) OP Battery became 4/73 (Sphinx) Special OP Battery. On 1st May 1993 Q (Sanna's Post) Battery and Headquarters Battery of the Regiment were amalgamated to become Q (Sanna's Post) Headquarters Battery. The majority of the locating troops in Q Battery were posted to other locating Batteries and troops within the Royal Regiment.

In late 1993, the Regiment carried out a Regimental Arms Plot from Dortmund to Catterick in North Yorkshire. After nearly nine months of unsettled transit period working in Towthorpe line, Strensall, near York, the Regiment moved into the former RAF Catterick Barracks, now renamed Marne Barracks alongside the A1. Co-locating with the Regiment's Artillery Support Unit, 8 (Artillery Support) Regiment, RLC.

In October 1994, the Regiment deployed to Northern Ireland again, this time to South Armagh as the Drumadd Roulement Battalion (DRB). K Battery was deployed to Bessbrook with P Battery being deployed in both Keady and Middletown, however the tour was cut short due to the IRA cease-fire.

On their return to Catterick the Regiment was busy carrying out its primary role training in addition to supplying soldiers to man a permanent special OP Patrol to Bosnia and various overseas exercises.

In early 1996 the Regiment was called upon to assist the Derbyshire civil authorities during a fire-fighters dispute (Op. FRESCO), a commitment led by K (Hondeghem) Battery. In addition, the Regiment supplied soldiers to 3 RHA for an operational tour of Northern Ireland.

On 1st April 1997, the Regiment rejoined 1st Artillery Brigade on its reformation as an operational element of the UK's framework nation commitment to Allied Rapid Reaction Corps (ARRC). In addition, on 1st April 1997, 4/73 Battery was formally committed to the Joint Rapid Deployment Force (JRDF). The Battery's commitment to the JRDF was to maintain six patrols and a command and control element ready to deploy at short notice worldwide with the Force.

On 10th June 1997, the Regiment, less 4/73 Battery deployed to Cyprus on Operation Tosca. Taking over responsibility for Sector 2 of UNFICYP from 32 Regiment RA. Soldiers from 1 RHA, 3 RHA, 32 Regt RA, 1 DWR, 1 RRW, 9 Parachute Squadron RE and soldiers from the TA reinforced the Regiment for the tour. Sector 2 covered the UN Buffer Zone in the area of Nicosia. P Battery deployed as Line Battery West and K Battery as Line Battery East. The tour was a great success and the Regiment returned to Catterick on 10th December 1997.

Following a period of leave, the Regiment returned to work in mid-January 1998 and immediately started the preparations for the re-roling. Because of a decision to transfer MLRS to the TA, it was decided that 5th Regiment would re-role from MLRS/OP to become a Surveillance and Target Acquisition (STA) Regiment. The Regiment would also assume responsibility for the provision of the Headquarters Force Artillery (HQ Force Arty) for the Allied Command Europe Mobile Force (Land) (AMF(L)).

The STA Headquarters also provides the Divisional Survey Troop, which provides accurate survey for the STA Batteries and other RA Regiments. The Force Artillery AMF(L) role was lost in 2002, however the Troop is still going, supplying command and control at Regimental and Brigade level. This Troop also includes a Meteorlogical detachment for use at Divisional level.